Predictive Modeling of Quantum Computing Development and its Impact on Blockchain Security
Miljenko Švarcmajer, Dina Šabanović, Mirko Köhler, Ivica Lukić · IEEE Access · 2026
Quantum computers pose a long-term threat to classical cryptographic systems, including those used in blockchain platforms. While prior work has estimated the number of logical qubits required to compromise cryptographic schemes such as RSA and ECDSA, relatively few studies have modeled when such quantum capacity might realistically be achieved. In this paper, we construct a time-series dataset of publicly documented gate-based quantum processors developed between 2016 and 2025. We estimate the number of logical qubits under three fault-tolerance scenarios and apply forecasting models based on exponential trend analysis. Our results provide year-by-year projections for when quantum computers may reach logical qubit thresholds associated with widely used cryptographic schemes. These projections are mapped to specific blockchain security mechanisms, offering a practical timeline for transition planning toward post-quantum systems. These projections should be interpreted as indicators of logical qubit availability rather than precise estimates of full cryptanalytic execution timelines.